Am Montag, den 22.12.2014, 16:32 +0800 schrieb Sean Cross:
> Some PCIe ports gate power to the slot. In order to prevent system lockup,
> these boards must enable power to the slot before attempting communication
> over the PCI bus.
>
> Signed-off-by: Sean Cross <xobs@xxxxxxxxxx>
Reviewed-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> ---
> .../devicetree/bindings/pci/fsl,imx6q-pcie.txt | 3 +++
> drivers/pci/host/pci-imx6.c | 27 ++++++++++++++++++++++
> 2 files changed, 30 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> index 6fbba53..a806b68 100644
> --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> @@ -13,6 +13,9 @@ Required properties:
> - clock-names: Must include the following additional entries:
> - "pcie_phy"
>
> +Optional properties:
> +- bus-supply: A regulator that controls power to the entire bus
> +
> Example:
>
> pcie@0x01000000 {
> diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
> index 69202d1..8e4f957 100644
> --- a/drivers/pci/host/pci-imx6.c
> +++ b/drivers/pci/host/pci-imx6.c
> @@ -22,6 +22,7 @@
> #include <linux/pci.h>
> #include <linux/platform_device.h>
> #include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> #include <linux/resource.h>
> #include <linux/signal.h>
> #include <linux/types.h>
> @@ -39,6 +40,7 @@ struct imx6_pcie {
> struct pcie_port pp;
> struct regmap *iomuxc_gpr;
> void __iomem *mem_base;
> + struct regulator *bus_supply;
> };
>
> /* PCIe Root Complex registers (memory-mapped) */
> @@ -523,6 +525,7 @@ static struct pcie_host_ops imx6_pcie_host_ops = {
> static int __init imx6_add_pcie_port(struct pcie_port *pp,
> struct platform_device *pdev)
> {
> + struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
> int ret;
>
> if (IS_ENABLED(CONFIG_PCI_MSI)) {
> @@ -544,9 +547,22 @@ static int __init imx6_add_pcie_port(struct pcie_port *pp,
> pp->root_bus_nr = -1;
> pp->ops = &imx6_pcie_host_ops;
>
> + if (imx6_pcie->bus_supply) {
> + ret = regulator_enable(imx6_pcie->bus_supply);
> + if (ret) {
> + dev_err(pp->dev,
> + "unable to enable bus supply: %d\n", ret);
> + return ret;
> + }
> + }
> +
> ret = dw_pcie_host_init(pp);
> if (ret) {
> dev_err(&pdev->dev, "failed to initialize host\n");
> +
> + if (imx6_pcie->bus_supply)
> + regulator_disable(imx6_pcie->bus_supply);
> +
> return ret;
> }
>
> @@ -588,6 +604,17 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
> }
> }
>
> + /* Fetch bus supply */
> + imx6_pcie->bus_supply = devm_regulator_get_optional(&pdev->dev, "bus");
> + if (IS_ERR(imx6_pcie->bus_supply)) {
> + ret = PTR_ERR(imx6_pcie->bus_supply);
> + if (ret == -EPROBE_DEFER)
> + return ret;
> +
> + dev_err(&pdev->dev, "unable to get bus-supply\n");
> + return ret;
> + }
> +
> /* Fetch clocks */
> imx6_pcie->pcie_phy = devm_clk_get(&pdev->dev, "pcie_phy");
> if (IS_ERR(imx6_pcie->pcie_phy)) {
--
Pengutronix e.K. | Lucas Stach |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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